Matter and Radiation Flashcards
What is the charge of a proton?
+1.6x10⁻¹⁹
What is the charge of an electron?
-1.6x10⁻¹⁹
What is the mass of a proton/neutron?
1.67x10⁻²⁷
What is the mass of an electron?
9.11x10⁻³¹
What is specific charge?
The charge of a particle divided by it’s mass.
What force holds together the nucleus?
The strong nuclear force.
At what distances does the strong force attract?
3-4fm
At what distances does the strong force repel?
distances less than 0.5fm
How do you work out the energy of a photon?
E = hf E=hc/λ E = energy h = Planck's Constant f = frequency c = speed of light λ = wavelength
How are em waves emitted?
em waves are emitted when a charged particle loses it’s energy. This can happen if an electron in a shell moves to a lower shell or if a fast moving electron slows down.
How do we calculate the wavelength of a wave in a vacuum?
λ = c/f
What happens when antimatter particles and matter particles meet up with each other?
They annihilate each other and release photons.
What happens in beta - decay?
A neutron decays into a proton, electron and an antineutrino (β- particle). A W⁻ Boson is used as an exchange particle.
What happens in beta + decay?
A proton decays into a neutron, positron and a neutrino (β+ particle). A W⁺ Boson is used as an exchange particle.
What are the six quarks in the standard model?
Up, down, top, bottom, charm and strange.
What are the four gauge bosons in the standard model?
photon, W, gluon, Z
What are the six leptons in the standard model?
Electron, electron neutrino, muon, muon neutrino, tau, and tau neutrino.
What is a hadron?
Hadrons are particles and antiparticles that can interact through the strong force and all other fundamental interactions.
e.g. protons, neutrons, π mesons, K mesons
What is a lepton?
Leptons are particles and antiparticles that can only interact through the weak force.
What is the only stable hadron?
The proton is the only stable hadron. All others eventually decay through the weak interaction.
What is a baryon?
Baryons are protons and all other hadrons that decay into protons.
What is a meson?
Mesons are hadrons that do not decay into protons.
e.g. pions and kaons
